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No protection against overflow/underflow when setting values

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#66 5 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
backend

Research direction

The issue names no files, tests, or entry points. Start by reproducing the builder.longOut example, then trace how values are passed to EPICS for the listed numeric, string, and waveform cases. Done means the relevant out-of-range or oversized values are validated with a warning or error, with coverage for the cases investigated.

Written by the indexing model from the issue text.

Description

bug

pythonSoftIOC provides no protections against overflowing data type limits.

The most obvious example of this is longIn/Out, due to the unbounded size of Python3's int type. No warning or error is raised if you attempt to do the following:

builder.longOut("TEST", initial_value=9999999999999)

[...]$ caget TEST
PREFIX:TEST 1316134911

The value is truncated, but no warning is given.

This issue should also investigate all other types, and consider adding validation to the incoming values before passing to EPICS.
Possibilities include ( but are not limited to):

  • Huge floating point values
  • Tiny floating point values
  • Strings that may be silently truncated, especially when unicode is in use
  • Waveforms when the value being set is longer than the NELM of the record
Dominant language
Python
Stars
47
Forks
15
Avg merge
1d 18h
Merged PRs (30d)
1

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